A convenient procedure for the synthesis of fipronil sulfide, one of severa
l active metabolites identified from the insecticide fipronil, has been dev
eloped. Reduction of fipronil with trifluoroacetic anhydride-sodium iodide
in acetone, followed by Rash chromatography afforded fipronil sulfide in 60
% yield and > 99.9 percent purity. This represents the first direct synthes
is of this key metabolite from fipronil. (C) 2001 Elsevier Science Ltd. All
rights reserved.